Use of trailers with bicycles is increasing as cyclists discover that trailers provide ways of increasing the utility and capacity of their cycles. Bicycle trailers have been developed for various use, such as carrying children, shopping, and hauling laundry and other loads, and have been used behind touring cycles to expand load capacity beyond conventional bags and panniers.
There are various structures for connecting bicycle trailers to bicycles. Some connections attach to the bicycle seat post. These types of connections result in an attachment point above the center of gravity of the bicycle. This adversely affects the braking power of the bicycle, particularly as most bicycle trailers do not have independent braking.
Other known bicycle trailer hitches attach to the rear-most bicycle frame members, also known as stays, by means of clamps which are bolted or strapped to the frame and which encircle the stays. The clamps must withstand the stress as a result of trailer movement. Such stresses may cause the clamps to slide along the stays, thus working themselves loose. Sliding clamps also mar the finish of the bicycle. The clamps may be time-consuming to attach and remove and normally require the use of tools to attach and remove the clamps. Additionally, different clamp configurations may be required, as various sizes of stays are used on bicycles, some bicycle frames may have different sized stays used in their construction. Likewise, the angle between the stays may vary with different bicycle designs and sizes. Furthermore, on some bicycles, the stays are not co-planer, and thus require a stay-clamping hitch to be twisted for installation. Another trailer hitch is that disclosed in U.S. Pat. No. 4,721,320 to Creps et al., which teaches a clamping arrangement. While this clamp has been proven successful for towing trailers behind a bicycle, it is bulky, and does not fit all bicycles, especially those bicycles having mono-stays, and some bicycles with hub brakes.
Other types of connections are hitches that employ additional structures which attach to the rear axle of the bicycle, and thus become a modification of the bicycle. Such attachments may be extensions to the axles, which provide for the attachment of a trailer, such as that shown in U.S. Pat. No. 5,516,131 to Novotny.
In view of the aforementioned shortcomings in known bicycle trailer hitches, there is a need for a bicycle trailer hitch which fits the greatest possible number of bicycles, i.e., a nearly universal hitch, regardless of stay sizes and angles, provides heel clearance for large footed riders on bicycles having short chain stays, does not rely on clamps bolted to the stays, does not require modification of the bicycle, is easily installed and removed, may be transferred from one bicycle to another, and provides a safe, secure, and convenient mechanism for attaching a bicycle trailer to a bicycle.